Auxiliary spring for pressure gauges



Dec. 26, 1922. 1,439,975.

F. W. PETERSON.

AUXILIARY SPRING FOR PRESSURE GUAGES.

FILED NOV-19,1920- g, 6% any performed, an attachment remaining graduations vention to manner that when which:

is removed for Patented Dec, 26?, 1922 [reams area FRANK ELDOIU PETERSON, OECHICAGO, ILLINOIS.

AUXILIARY SPRING- FOR PRESSURE GAUGES.

Application filedllovember 19, 1920. 2 Serial No.

To all whom it may concern:

Be it known that I, FRANK'WHELDON PETERSON, a citizen of the United States,

and a resident of Chicago, in the county of 5 Cook and State of Illinois, have invented a certain new and useful Auxiliary Spring for Pressure Gauges,"of which the following is a specification.

The object of my invention is to provide 10 in a dynamometer having a graduated scale and a movable index member therefor, the movement of which from one graduation to another is designed to indicate a predetermined number of units of pressure or work adapted to be adjustably applied to and to coact with the mechanism ofsaid index member when the said member has reached a predetermined graduation on the dial, so that each of the may be made to read a greater number of units of pressure or Work performed from which they were or inally intended to read.

ore specifically provide an attachment adapted to be applied to the Bourdon type of pressure gauge, havinga circular tube for operating the index member, andwhich tends to straighten out when pressure is applied,

30 and to provide in connectionwith such tube detachable'and adjustable means whereby when the index member has reached a predetermined point on a graduated scale, the attachment will act on said tube in such a isters one additional will representa greater number of units of pressure than was originally represented by said degree of move 40 that when not in engagement with said tube member it will not interfere with in of the original mechanism. I w

ith these and other objects in View my invention consists in the construction,

the workcontem plated are attained, as hereinafter more fully set forth, 'pointed out in my claims trated in the accompanying drawings, in

Figure 1 is a back elevation of a Bourdon type of pressure gauge showing the manner in W ich my improved device is attached. The back of the said pressure gauge being the "purpose of showing the mechanism:

it is the object of my, inv the index-member reg-. degree on said scale, itv

ment, and so constructed arrange 25 ment' and combination of "the various parts of the device, whereby the objects Figure 2 is a front elevation of the same showing the scale graduated as is used in connection with my improved device; and

igure 3 is a detail, end elevation of my improved device, showing fragments of the pressure gauge.

eferring to.the accompanying drawings I have used the reference numeral 10 to indicate the casing of a pressure gauge which. is of the Bourdon type. The sald gauge being provided with a screw-threaded portion 11 which is designed to be mounted in the usual manner. The bottom portion of the casing 10 is provided with a base member 12, which is designed to carry the Bourdon tube 13, one end of nected with the pipe 11. T of the tube 13 is provided With a hook member 14, which is pivotally connected to a link 15, said link being operatively connected with the dial operating gears and pinion 17 he pinion 17 is mounted on aishaft 18 which is designed to carry the index member 19. This member 19 is mounted adjacent to a graduated scale 20, which is provided with a series of circular graduations 21. The graduations ranging from one to ten, being spaced equal distance apart. I have provided an additional graduation 22, the purpose of which will be explained later.

which is operatively con-' he opposite end 7 It will be evident from Figure 2 that the graduation scale indicated thereon is designed for low pressure work which requiresra comparatively accurate reading, but it often happens that itis desirable to use such a pressure gauge in work which requires a certain degree of accuracy under low pressures, but which may be also capa'ble of indicating less accurately higher pressures.

viding an independent mechanism for indicating the higher pressure, I have Vided means that low pressure gauge which will roughly indicate the higher pressure by providing an additional numeral22; said attachment being used in connection with the ordinary mechanism without interfering with the same while .workingunder low pressure; p

have provided on To accomplish this I To accomplishthis without pro- 1 pro-' I may be attached to the graduatedscale' indicated by the the member 12 an inclinedv extension 23,;

whichis designed to carry a set-screw 24 which is operatively connected with a spring member 25; said spring 25 being provided I with a- U-shaped loop 26 so as to. provide adjustment between the member 23 and the,

said spring member. r

r The opposite end of the spring 25 is provided with a loop 27 which is so constructed that it will surround the hook member 14, as clearly shown in Figures 1 and: 3. In Figure 1 I have shown the free end of the tube 13 and the hook member 14 in its normal position, or in that position in which the index '19 indicates zero on the graduated scale. 7

When pressure applied to the tube 13, it will expand slightly and the hook member 14 will be moved upwardly which will cause said tube the index 19 to travel over the scale 21.

When the said index tion 10, the loop 27 is adjusted by means of the set-screw 24, so that it is by the said hook 14. A further movement of the member, 14 caused by an increase in pressure within the tube 13, will be retarded by the tension of the spring 25 in such a manner that when the index 19 has passed through a space equal to one degree on the scale 21, it may be made to indicate a pressure equal to twenty of the original degrees, which would in this particular case be thirty,

on the said scale.

A greater number .of degrees, however, may be made to read in the said space by increasingthe size'of the spring 25 or vice versa. Thus" it will an attachment of simple, durable and inex- 1 pensive construction which may be used in connection with and attached to the ordinary pressure gauge in such amanner' that the said pressure gauge may be used to indicate higher pressures than from which the .said gauge was originally intended, or the attachment may be built in and made a part of the gaugeifso desired.

Some changes may be made in the'construction and arrangement of the parts of ,my improveddevice without departing from the real spirit and purpose of my invention, and it is-my intention to cover any modified forms of structure or use 0 mechanical equivalents which may be rea sonably included within their scope.v jl'claim as my invention: 1. A pressure gauge comprising has reached the posijust engaged ing each of its ends provided with a as indicated be seen that I have provided spring being providedw-ith by my claims a casing Y having a. graduated scale of equal divisions, j

some of said divisions being provided with characters toindicate single units of pres sure, the remaining divisions being subdivided and provided with characters to ind1-' free end of said tube :for actuating said.

index member, the said mechanism being so arranged that as pressure. is applied to, the the index member Wlll move over the division indicating single units of pressure, a retarding device designed to engage the free end of said Bourdon tube as the indicator reaches the divisions having the characters indicating a plurality of units, said device comprising a helical spring havongitudinally arranged portion, one of said portions being provided with a loop, means for adjustably securing said loop portion to the casing of said gauge, the opposite longitudinal member of said spring being provided with a loop. designed to be engaged by the hook of said Bourdon tube when the index member has reached the division indicating a plurality of units, the longitudinal axis of said spring being arranged in a tangential relation with said Bourdon tube.

2. A pressure gauge comprising a casing, an index member, a Bourdon tube having one end fixed to said casing and the other end provided with a hook, means operatively connected to the free end of said Bourdon tube her, a helical spring, having each of its ends provided with a longitudinally arranged portion, with a loop, means for adjustably securing said loop portion to the casing of said gauge, the opposite longitudinal member oi said a loop designed to be engaged by the hook of said Bourdon tube when the said index member has reached a predetermined position, the longitudinal axis of said spring being arranged in a tangential relation wi said Bourdon tube.

-Des--Moines FRANK Iowa November 4, 1920.

olperating said.

for operating said index memr one of said portions being provided wi 1Ei.DoN PETERSON. 

